Filtration respirators, or face masks, have been widely used in the past to protect the respiratory system from particulate or chemical agents. These protective face covers are designed to minimize the transmission of contagious diseases or to protect the respiratory system from toxic substances or allergens in the surrounding atmosphere.
Protective face masks are generally used for preventing the transmission of contagious diseases, as well as to protect from inhalation of industrial or city dust or dirt, chemicals, allergens, and the like that may be present in the atmosphere. These masks are used to maintain a private, enclosed space around the breathing orifices when a person is in close proximity to other persons, or if an undesirable atmospheric agent is present. Additionally, infectious persons can wear masks to protect other people in the vicinity from their pathogens.
A variety of masks have been proposed which have different features, such as different ways of retaining the mask in place, providing different degrees of comfort for the wearer, having inhaling or exhausting valves, different types of seals around the mask for tighter sealing of the mask to the wearer's face. Other features include impregnating the mask with certain chemicals to make the mask more effective against air borne substances, and sterilizing the mask to enhance its cleanliness.
However, when the wearer wishes to eat or drink, the above masks must be removed so that food or drink can be imbibed. Of course, removing the mask means that the face is no longer protected. In addition, the mask may be misplaced, lost or contaminated.
Examples of some of these types of masks can be found in U.S. Pat. No. 2,494,406, which shows a protective mask which has elastic temple straps attached to the mask to enhance the conforming to the face of the wearer. In addition,
U.S. Pat. No. 6,098,201 shows a molded face mask made of a plastic sheet in which a deformable wire is embedded so that the mask better conforms to the wearer's face.
U.S. Pat. No. 4,827,923 shows a protective facial mask that slips over the user's head.
U.S. Pat. No. 6,123,077 discloses a mask with a flat central panel to which other panels are joined through a fold line, seam, weld, or bond.
U.S. Pat. No. 4,974,586 shows a breathing mask which comprises an inhalation valve disposed in an opening of the wall of the mask. The inhalation valve opens at a sufficiently low breathing pressure to make it comfortable.
U.S. Pat. No. 5,699,792 shows a face mask with an enhanced facial seal.
U.S. Pat. No. 5,701,892 shows a two-sided chamber held away from the entrance of the nostrils and the mouth by a moldable support.
U.S. Pat. No. 4,941,470 shows a face mask having pleats formed therein and a method for fabricating the mask.
U.S. Pat. No. 6,394,090 shows a respiratory device having first and second lines of demarcation bisected by a fold so that the device can be folded.
U.S. Pat. No. 4,856,509 discloses a face mask containing a chemical or biological agent that destroys microorganisms such as viruses and bacteria.
U.S. Pat. No. 5,819,731 shows a face mask having a combination of adjustable ear loops and drop down band for a snug fit.
U.S. Pat. No. 5,717,991 shows a disposable sanitary mask comprising a cover panel section adapted to cover the wearer's nose and mouth and a pair of ear loops and panel sections to prevent the mask from losing its shape.
U.S. Pat. No. 5,735,270 discloses a disposable foldable face mask with face seal characteristics for a high efficiency filtering medium.
U.S. Pat. No. 6,213,125 discloses a device for protecting the face of the wearer including a gas pervious mask dimensioned to fit over the nose and mouth and a shield to protect the eyes of the wearer.
U.S. Pat. No. 6,332,465 discloses face masks having elastic polyolefin thermoplastic bands attached thereto by heat and pressure.
GB 2,072,516 discloses a face mask having one or more exhalation valves that flex so that the mask is completely closed during inhalation, and an opening is opened during exhalation.
U.S. Pat. No. 4,589,408 discloses a surgical face mask and hood that substantially completely surrounds the head of the wearer and reaches to the neck where it is fastened by a length of elastic. There is an opening for the eyes so that the wearer can see.
CA 2,269,387 describes a cold weather face mask that fits snugly on the face to cover the cheeks and nose of the wearer as well as the chin and jawbones.
U.S. Pat. No. 6,055,982 discloses a face mask which prevents transmission of air borne aerosols, particulate matter, and/or liquids, having an enhanced fluid barrier between the periphery of the mask and the wearer's face.
U.S. Pat. No. 7,044,127 discloses a face mask that has a self-closing opening through which the wearer can take nourishment or liquids without removing the mask.
Published Application No. 2009/0151734, discloses a combination mask and goggles having a replaceable filter over the mouth area that can be replaced without removing the plastic structure to which the removable filter is attached.
U.S. Pat. No. 7,320,722, discloses a respirating protection device to whish can be attached a source for clean air.